Electric relay



Sept. 16, 1947. J. BIERENFELD 2,427,437

ELECTRIC RELAY I Filed Feb. 10, 1944 2 Sheets-Sheet 1 INVENTOR. I I IIII BY Jqsef 5/0 6/11 e/d Sept. 16, 1947. BIERENFELD 2,427,437

ELECTRIC RELAY Fil'ed' Feb. 10, 1944 2 Sheets-Sheet. 2

WWW E 659 wsuur/olv I 4 I I g I p 5 aw 7 W 42 W V E?- I mmvrm INSULATIONJosef Blef'C/W e/d Patented Sept. 16, 1947 ELECTRIC RELAY JosefBierenfeld, Milwaukee, Wis., assignor to Square D Company, Detroit,Mich., a corporation of Michigan Application February 10, 1944, SerialNo. 521,779

6 Claims.- 1

This invention relates to relays and more particularly to thermaloverload protective relays.

One object of the present invention is to provide a relay automaticallyoperable on the occurrence of an overload current and having improvedand simplified reset mechanism therefor.

Another object of the invention is to provide an overload protectiverelay wherein the contacts are maintained in separated position onresetting of the overload responsive means. e

Other objects and features of the invention will be readily apparent tothose skilled in the art from the specification and appended drawingillustrating certain preferred embodiments in which:

Figure 1 is a rear elevational view of the relay according to thepresent invention.

Figure 2 is a top plan view of the invention,

Figure 3 is a vertical sectional view taken on the line III-III ofFigure 1. v

Figure 4 is a, detail sectional view taken on the line IV-IV of Figure3. I

Figure 5 is a. sectional view taken on the line V-V of Figure 3.

Figure 6 is a fragmentary view illustrating certain details similar toFigure 5 and showing the tripped position of these details.

Figure '7 is a sectional view taken on the line VII-VII of Figure 3.

' The particular relay illlustrated here is adapted for the protectionof electric energy translating devices by opening the energizing circuitthereof on the occurrence of a current therethrough exceeding apredetermined value.

The relay, as shown in the drawings, embodies a base I formed ofinsulating material and comprising a pair of base sections 2 and 3.Section 2 is provided with an elongated recess 4 extending horizontallytherein for substantially the entire length thereof as shown in Figure'7. The recess 4 is enlarged at its left hand end to form a chamber 5and at its right hand end to form a chamber 6. A conducting element 1 isdisposed in chamber 5 adjacent the top defining wall 8 thereof andhaving an extremity disposed in a slot formed in a back wall 9 ofsection 2,'which extremity is closely received therein to effect asupport for the element 1. An elongated resilient member II is securedat one end |2 to the conducting element 1 by a rivet.l3 and extends thelength of recess 4 and into chamber 6; upon the end H of the resilientelement II which is disposed in chamber 6 is mounted a contact elementl5. Disposed above contact element l5, for oooperation therewith, is acontact element It, which contact element is riveted to a conductingelement l1. Thev conducting element also has an extremity thereofclosely received by a slot provided in the back wall 9, in the samemanner as conducting element 1, and which effects a support therefor.Base section 2 provides horizontally spaced ledge formations l8 and I9which effect a support for a thermal responsive unit 2|. The unit 2| initself forms no part of the present invention and will be but brieflydescribed. Unit 2| comprises a conducting heating element 22 supportinga ratchet wheel 23 which is held against rotation by a fusible alloyadapted to be melted by an overload current in conventional manner topermit the rotation of wheel 23 under the force of mechanism to bedescribed. A unit.

similar to unit 2| is more fully described in Patent No. 1,752,514issued to H, L. VanValkenburg. A pair of conducting members 24 and 25are disposed respectively on ledge formations I8 and I9,

with member 24 being located betweenprojecting formations 26 and 21provided on ledge I8 and with member 25 located between similarprojecting formations 23 and 29 on ledge It. The conducting members 24and '25 are provided with projections 3| which extend into slots formedin the projecting formations 21 and 29 and which are closely receivedthereby to preventmovement of the conducting members with respect to thebase 2. Terminal studs 32 are carried by the conducting elements 24 and25 for the securance of circuit wires thereto. The overload unit 2| issecured to the conducting members 24 and 25 by a pair of studs 33 tothereby place the unit 2| in an electrical circuit. With the unit 2| inposition, the conducting members 24 and 25 will be firmly positioned andcannot be removed from the base without first removing unit 2|.

Base section 3 is adapted to be placed adjacent base section 2 and has aplurality of slots formed in walls 34 and 35 thereof, with certain ofthe slots adapted to closely receive extremities 36 of the conductingelements! and I1 and with other of the slots closely receivingprojections 31 of the conducting elements 24 and 25. This arrangementprovides for the proper location of base section 3 with respect to basesection 2 and firmly positions the conducting elements 'I and IT on baseI, the latter elements I and I1 resting on flat surfaces 38 provided onbase Section 3. A pair of terminal studs 39 are carried by conductingelements I and I1 whereby electrical lead-in wires may be secured. Apair of studs 4| maintains the base sections 2 and 3 in assembledrelationship. Base section 3 provides wall surfaces which substantiallyseal oi! recess 4 in section 2 10 provide a contact chamber which istotally enclosed except for an opening 42 leading thereinto. Anactuating member 43 has one extremity 44 extending through opening 42and projects over the resilient switching member II for actuationthereof in a manner to be described. Walls 34 and 35 of base 3 areseparated by a recess 45 which receives the reset mechanism 46. Thereset mechanism 49 includes a plate-like member 41 having longitudinalwing' projections 48 which lie in recesses 49 whereby the member 41 isguided for rectilinear movement. Member 41 pivotally carries a latch 5|having a latching portion 52 adapted to engage the ratchet wheel 23 tomaintain member 41 in a predetermined position. A spring 53 has one endthereof disposed about a portion of the latch 5| and the other enddisposed within a recess 54 biases member 41 upwardly and latch 5|toward wheel 23. The latch 5| is provided with a projecting formation 55which is received within a recess 56 in member 41 to limit the extent ofclockwise movement of latch 5| and insure its always being in properposition to properly engage wheel 23. The switch actuating member 43 hasan extremity 51 thereof extending through an opening 58 in member 41 andhaving a defining surface thereof oneageable with this extremity wherebymember 43 when released by latch 5| can effect pivotal movement ofmember 43 about edge 6| 0; a formation 62' on base 3 in a manner and fora pu pose to be more iully described A pair of insuLting members 63 and6d are secured 3.0 t me bar. 3 by the Studs ti'and serve to confinemember 41 to limit its movement to a vertical one. Each of theinsulating members 53 and 64 have openings therein through which exremity 51 of actuating member 43 extends.

Disposed on the back of base section 3 is a bracket 65, the centralportion 65 of which is pan shape to provide a space 61 between portion56 and the back surface of the insulating member 54, and having two legportions 98 and 69 through which the studs 4| also pass to therebysecure the bracket to base 3. A generally L- shaped actuating member ormanual operator 10 has the longer leg 12 thereof disposed through anopening 13in bracket 55 and extends into the space 61 between insulatingmember 54 and portion 65. The shorter leg 1| of the member 18 extendsover member 41 and is adapted under certain circumstances to effectmovement-thereof as will be described. Also disposed within space ,61 isa member 14 having an end 15 pivotally secured to extension of leg 12 ofthe actuating member 10 by a pin 16. Member 14 is provided with anarcuate slot 11 in which is disposed the shank 18 of a pin 19 secured toportion 55 of bracket 55. A spring 8| has one extremity 82 thereofsecured to portion 58 and the opposite extremity 83 is fastened to thepivoted member 14 and continually biases member 14 upwardly andmaintains actuating member 10 in its uppermost position. The use of aradial slot 11 in member 14 extends the distance that the manualoperator can be moved downwardly; upon initial movement of member 10,member 14 is pivoted about pin 13 in the lower end of the arcuate slot11 until its free end engages the end 51 of switch actuating member 43and rotates it to the position where it holds the relay contacts open.Thereafter, member 14 pivots about its engagement at end 84 with themember 43, moving the arcuate slot 11 alon pin 19 as shown in dottedlines in Figure 1. In this latter movement, leg 1| engages member 41, ifreleased, and moves it to reset position.

A pair 01 mounting studs 85 and their nuts 88 are carried by base 2 andprovide means for securing the relay in a desired location.

In the operation of the relay, the movable contact i5 is normally heldin engagement with the stationary contact l8 under the inherentresiliency of the switching member ii. To effect a manual switchingoperation, the manual operator 19 is manually moved downwardly againstthe bias of spring 3| to rotate the pivotal member 14 counterclockwiseabout its pivot pin 15 and cause end, 84 thereof to force the actuatingmember 43 to pivot counterclockwise about edge SI and bring the end 44into engagement with switching member II to move it to disengage contactl5 from contact Ili. Release of manual operator 10 will allow it toreturn to its normal position of rest under the force exerted by spring8|.

On the occurrence of an overload in the circuit in which unit 2|islocated, sufllcient heat is developed to melt the solder holdingratchet wheel 23 to permit its turning to thereby release latchingportion 52 and permit spring 53 to move member 41 upwardly This upwardmovement of member 41 will brzng surface 59 of opening 58 in member 41into engagement with extremity 51 01"" the switch actuating member 43 toeffect a pivoting thereo about edge 6| to engage and move SWi'LCh memberH to disengage the contacts an break the circuit,

To reset the latch 5|, the manual operator 10 is moved downwardly tobring leg 1| thereof into engagement with member 41 and thus the lattermember can be moved into a position where the latching portion 52 mayreengage with ratchet wheel 23 and be held if the solder has solidified.In the downward movement of member 41. the surface 59 will be moved awayfrom switch actuating member 43 and ordinarily the resilient switchmember ll would move toward contacts engaged position, but as surface 59is being moved away, the pivotal member 14 is being actuated to bringits projecting portion 84 into engagement with member 43, ashereinbefore described, to maintain a force upon switch member I toretain the member I] in contacts disengaged position. Release of manualoperator 10 will then allow the parts to move in the manner describedand the contacts to engage. It is apparent that with a relay asdescribed, it is not possible to maintain the contacts engaged onoverload because the contacts will be opened either by the upwardmovement of member 43 or by the action of the reset mechanism if it isheld in reset position.

While certain preferred embodiments of the invention have beenspecifically disclosed, it is understood that the invention is notlimited thereto, as many variations will be readily apparent to thoseskilled in the art and the invention is to be given its broadestpossible interpretation within the term of the fOllOWillg claims:

What is claimed is:

1. An electrical relay comprising a' stationary contact, a movablecontact, a switching arm connected to the movable contact and constantlybiased to contacts engaged position, current responsive meansior'efiecting movement at the switching arm into contacts disengagedposition upon the occurrence of a current overload through the relay, amanually operated element having a pin and slot mounting and operable toprevent the return of the switching arm to contacts engaged position,means for rotating said element in its initial manual actuation aboutthe engagement of said pin at one end of the slot to initially obstructthe return of the switching arm to contacts engaged position, and forthereafter maintaining said obstruction while effecting relativemovement of the pin and slot to permit further movement of the manualelement, and means for effecting the return of the current responsivemeans to its normal inoperative position during movement of saidelement.

2. An electrical relay comprising a stationary contact, a movablecontact, a switching arm connected to the movable contact and constantlybiased to contacts engaged position, an element engageable with saidswitching arm to mov it to contacts disengaged position, an actuatorbiased to move said element but normally latched in inoperativeposition, current responsive means for releasing said latch to permitsaid actuator to move said element to separate the contacts, and manualmeans for returning said actuator .to its latched position and includinga member engageable with said element to retain it in contactsdisengaging position, said member having ,a pin and slot mounting with abiasing means for said member-at the side of said pin opposite to thepoint of engagement with said element, initial movement of said manualmeans effecting rotation of said member about the point of engagement ofsaid pin with one end of said slot to immediately effect a restraint onsaid element, continued movement of said manual means to effect returnof the actuator causing relati movement between said pin and slotagainst said biasing means While the member pivots about its engagementwith said element.

3. An electrical relay comprising a stationary contact, a movablecontact, a switching arm connected to said movable contact, a pivotalelement having one end 'disposedto engage said switching arm and move itto contacts disengaged position, a pair of generally parallel slidemembers, both of which are biased upwardly, means for latching one ofsaid slide members in a downward position, current responsive means forreleasing said one of said slide members upon the occurrence of acurrent overload through the relay, said one of said slide members inits released position effecting movement of said element to move theswitching arm to contacts disengaged position, the second of said slidemembers being connected to move said element into contacts disengagedposition as said second of said members is moved downwardly, said secondof said members when so moved engaging said one of said members toreturn it to its latched position.

4. An electrical relay comprising a stationary contact, a movablecontact, a switching arm connected to the movable contact and constantlyI biased to contacts engaged position, an element engageable with saidswitching arm to move it to contacts disengaged position, currentresponsive means for moving said element to contacts disengaged positionon the occurrence of a cur-' rent overload through the relay, manualmeans for effecting the return 01' said current responsive means to itsnormal inoperative position including a floating member which pivotsabout one point in the initial movement of said manual means to engagesaid element and retain it in contacts disengaged position and, in thecontinued movement of said manual means to return the current responsivemeans to normal position, pivoting about the engagement of said memberwith said element, and biasing means for said member exerting a force onsaid element in said further movement of the manual means to overcomethe normal bias of said switching arm.

5. An electrical relay comprising a stationary contact, a movablecontact, a switching element carrying said movable contact and biased tocontacts engaged position, an operating element engageable with saidswitching element to move it to contacts disengaged position, anautomatic actuator, means biasing said actuator to move said operatingelement, current responsive means normally retaining said actuator innonoperating position but releasing the same upon the occurrence of acurrent overload to effect contact separation, and manually operablemeans for resetting said actuator in retained position and including afloating member pivoting about an axis, upon initial movement of saidmanual means, into engagement with said operating element to retain itin its contact disengaging position, and pivoting about its engagementwith said operating element upon further movement of said manual meansto reset the actuator whereby said contacts are maintained disengagedduring the resetting operation.

6. An electrical relay comprising a stationary contact, a movablecontact, a switching element carrying said movable contact and biasedinto contacts engaged position, a rotary member for moving saidswitching element to contacts disengaged position, a rectilinearlymovable member, means biasing said rectilinearly movable member to movesaid rotary member, current responsive means normally latching saidrectilinearly movable member in inoperative position but releasing thesame upon the occurrence of a current overload to effect separation ofsaid contacts, a second rectilinearly movable member manually operableto effect resetting movement of said first mentioned rectilinearlymovable member after an automatic operation, and a floating memberconnected to said second rectilinearly movable member, movement of saidsecond rectilinearly movable member eflfecting initial rotation of saidfloating member about a first axis into engagement with said rotarymemher and rotation thereafter about its engagement with said rotarymember while the first mentioned rectilinearly movable member is reset,whereby the contacts are maintained separated during the resettingoperation.

JOSEF BIERENFELD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNI'IfED STATES PATENTS Number

